At GDC China's Independent Games Summit in Shanghai, Kim Swift outlined the design lessons she's gleaned as she went from a student game developer with Narbacular Drop, to her professional work on Portal, Left 4 Dead 1 & 2, and now Quantum Conundrum.

“If you're looking to be a good designer, you owe it to yourself to learn everything you can. And I mean everything,” she began. “Learning how to sew when I was younger made it actually really easy for me to unwrap a 3D model,” adding, “If you're not learning something new on a day-to-day basis, then you're doing something wrong.”

But be humble, as well. “Sometimes your ideas aren't always great. One of the best abilities you can have in this industry is to take a step back.

“I have just as many crappy ideas as the next person,” she admits.

So how do you figure out if your ideas are actually good? Playtest, playtest, playtest.

“It is seriously one of the most important processes for game design,” says Swift. If players are learning the wrong things “It's not the player's fault -- it's your fault.”

Playtesting should begin with your team, who you should be very actively listening to. “If you have a small team, you have literally no excuse not to listen to your teammates in a small group,” she says. “If you don't trust your teammates to make the right choices and give valuable input, then you've probably chosen the wrong team.”

If you get into a situation where you have to cut features, she says you should “Focus down on the core mechanics that will make or break your game. ... Categorize features into 'integral,' 'somewhat important,' and complete 'wishlist.'”

When teaching new concepts, as with Portal, she says you need to first “teach a skill by itself, with very few distractions. Then you reinforce it. Show that skill to a player again and again and again, but make it a little more challenging this time.”

Swift says you should “reinforce newly-taught skills at least twice,” but then “give players an a-ha moment.” That is to say, after you've given people a few skills, bring them together; “this will make players feel really smart and accomplished.”

But don't be afraid to take risks either. “Strive for random things, because you really never know if it might take off,” says Swift, citing the “Still Alive” song in Portal as an example of a weird idea that paid off.

“The game industry right now is super weird. It makes no sense and it's kind of scary,” she concludes, noting the console transition, free-to-play gold rush, and mobile space.

“I have no idea what the next few years are going to look like. So as a small developer we have to stay on our toes, and adapt to whatever comes along.”